Surface grinder



April 14, 1964 J. A. BALL 3,128,578

SURFACE GRINDER Filed July 18, 1962 Z 41 3 1 z 2 1a zQ J 2 Sheets-Sheet 1 A ril 14, 1964 J. A. BALL 3, 8,5

SURFACE GRINDER Filed July 18, 1962 2 Sheets-Sheet 2 b flzzwor iz a ymj ler der United States Patent M 3,128,578 SURFACE GRINDER James A. Ball, Cedar Rapids, Iowa, assignor to The Morris Plan Company of Cedar Rapids, a corporation of Iowa Filed July 18, 1962, Ser. No. 220,931 (Filed under Rule 47(h) and 35 U.S.C. 118) 7 Claims. (Cl. 51-55) This invention relates to a surface grinder, and, more particularly, to a grinder wherein the entire work area is coverable in a single pass of the grinding wheel or cup.

The grinder to which the instant invention has application employs a vertical rotating spindle carrying a cup-shaped grinding element which is passed horizontally, arcuately over the work to be machined. Although grinders of this character have been known, they have been unable to reconcile compactness with grinding the entire area of a workpiece in a single passi.e., the workpiece had to be shifted relative to the grinder so as to dress the remainder of the surface. This problem is solved by the instant invention, and the provision of such a surface grinder constitutes an important object of the invention.

Another object of the invention is to provide a unique combination of grinder parts wherein the parts cooperate to stabilize each other so as to make possible a compact, sturdy mechanism.

Still another object is to provide a stabilized surface grinder equipped with positionable features that are readily acceptable for one-man operation.

Yet another object is to provide a surface grinder possessing unique lubricating and coolant facilities.

Other objects and advantages of the invention may be seen in the details of construction and operation set down in this specification.

The invention will be explained in conjunction with an illustrative embodiment in the accompanying drawing, in which- FIG. 1 is a perspective view of the inventive surface grinder;

FIG. 2 is a top plan view of the upper portion only of the grinder and as would be seen along the sight line 22 as applied to FIG. 1;

FIG. 3 is a side elevational view of the top work of the grinder and corresponds to the view seen along the sight line 33 as applied to FIG. 1; and

FIG. 4 is an enlarged elevational view, partially in section, of the upper portion of the apparatus and as would be seen along the sight line 44 as applied to FIG. 2.

First referring to FIG. 1, the numeral designates generally a base and which has an upper surface 11 providing a support 12 for work (not shown) to be ground. The work-holder or support 12 is suitably enclosed by an arcuately-shaped wall 13 which defines the limits of travel of a housing 14 carrying the grinding cup or wheel 15 (seen only in FIG. 4).

Now referring to FIG. 4, it will be seen that the upper surface 11 provides a pedestal mounting 11a for a vertically-extending post 16. The housing 14 is slidably, rotatably mounted on the post 16 and is maintained in a selected position by means of a lead screw 17 provided as part of an upper block or casting 18 rotatably mounted atop the post 16. The operation in general is as follows:

Operation in General The cup 15 is rotated by a motor 19 (see FIG. 4) and the hand wheel 20 coupled to the lead screw 17 is turned so as to bring the lower edge 15a of the grinding cup to the proper predetermined distance above the work 3,128,578 Patented Apr. 14, 1964 support 12. Thereafter, the housing is rotated over a circular are by means of the artisan grasping the hand bar 21.

The work when being ground is cooled by a coolant distributed through a ring or annular structure 22 suitably supplied through a flexible conduit 23 (see only FIG. 1). The coolant tank and pump can be suitably housed Within the base or pedestal 10 which is equipped with an access door 24 (again see FIG. 1). If desired, the coolant may be supplied and exhausted through fittings 25 and the pedestal itself may be anchored by means of bolts (not shown) extending through the apertured plate 26 provided at the bottom of the base 10.

The base 10 supports a splash pan generally designated 27, which provides the arcuate wall 13 previously referred to, and within the splash pan 27 the work support 12 is housedthis taking the form of a magnetic chuck, if so desired. 7

The post pedestal 11a is bolted or otherwise suitably anchored to the base 10 and is equipped with a rubber boot or collapsible sleeve 28 extending between the top of the pedestal 11a and the lower portion of the housing 14 (see especially FIG. 4).

The housing 14 includes a two-piece casting 29 with portions mating as at 29' which incorporates the motor 19 and which is bored as at 30 for the slidable, rotatable receipt of the post 16. The casting 29 is cored as at 31, and mounted therein is a threaded plug 32 which receives the lead screw 17, serving to support the casting 29 in a selected position above the surface 11.

The lead screw in turn, as pointed out before, is carried by the block 18 and is suitably supported therein by means of a bearing 33, the upper part of the screw 17 being unthreaded as at 17a and riding within a sleeve bearing 34 provided as part of the block 18.

The block 18 is equipped with a second bearing 35 which is interposed between an upper shoulder 36 of the post 16 and a confining recess 37 in the block 18. Thus, the block 18 is free to rotate on the post 16 to traverse the cup 15 over the work support 12.

The block 18 also fixedly carries a stabilizer bar or rod 39 which projects downwardly and is ensleeved within apertured lugs 40 provided integrally with the casting 29.

Consideration of FIG. 2 reveals that the axis 39a of the stabilizer bar 39, the axis 16a of the post 16, the axis 17b of the lead screw 17, and the motor shaft axis 19a are all essentially coplanar, so that the stabilizer bar 39 and post 16 provide an advantageous counterbalance for the weight of the motor portion of the casting 29, the entire casting being supported by the lead screw 17 which is interposed between the motor 19 and the post 16 and hence is eccentrically related to the post 16.

The upper portion of the post 16 is equipped with a post or column cap 41 suitably secured to the stub extension of the post 16 as at 16a by means of a screw 42 (seen only FIG. 4).

Still referring to FIG. 4, it will be seen that the mo tor shaft is provided in the form of a spindle 43 of some extentextending below the lower portion of the casting 29 as at 29a. The dependent shaft extension in this area is equipped with a conical portion 44 which supports an upper adapter 45 suitably apertured for tight seating on the conical portion 44. The extreme lower end of the spindle 43 is equipped with a nut 46 which urges the upper adapter 46 into clamping relation with the tapered spindle 44. The lower adapter 47, which is employed to tightly clamp the cup grinder 15 in the position shown, is secured to the upper adapter 46 by means of a tapered thread as at 47a (see FIG. 4).

Lubrication of the motor shaft or spindle is achieved initially in casting 29 and retaining the same therein by means of an outer labyrinth 48 which is supported on the spindle 43 and which cooperates with the lower portion 29a of the casting 29 in providing a seal as at 2%. The wheel or cup 15 is partially shrouded by the lower housing or shield 49, which is secured to the casting 29 as by bolts 5d.

In the operation of the device, the motor is started or stopped, as the case may be, by virtue of the pushbuttons 51 (see FIG. 1). Thereafter, the hand wheel 20 which may be equipped with suitable Vernier indicia as at 2011, is rotated to the desired height. The housing 14 then is caused to traverse the, work and substantial grinding can be achieved through the gradual lowering of the housing 14 by means of the hand wheel 20, one hand of the operator grasping the hand bar 21 while the other manipulates the hand wheel 20. The commercial embodiment of the invention is able to cover an entire work area 5" x in one pass of the wheel and achieves parallelism to 0.0002". To insure long wear-free life, the spindle is advantageously constructed of alloy steel, case hardened and ground, and runs in pre-loaded, self-lubricating bearings as at 52 and 53. Further maintaining the self-lubricating character of the motor and spindle assembly are oil slinger rings (not shown).

The spindle carries a cup or wheel 15 secured thereto in part by adapter 45, which has a 3.5" taper.

The compactness of the equipment can be seen from the fact that the floor space requirement is x 30", and the overall height of a bench model is 39". Such a grinder provides a maximum distance under the wheel of 6 /2".

While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of explanation thereof, many variations in the details herein given may be made by those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. A surface grinder, comprising (A) a base,

(B) an upstanding post on said base,

(C) a work support on said base adjacent to but spaced from said post,

(D) a housing slidably, rotatably mounted on said post,

(E) a motor mounted in said housing and equipped with a grinding cup axially related to the motor, said cup being positionable over said support, and

(F)'means on said post for sliding said housing thereon and for stabilizing said housing, said means ineluding an elongated rod-like member arranged parallel to and spaced from said post, said housing being slidably mounted on said member with said post being positioned between said member and motor.

2. The grinder of claim 1 in which said means also includes an elongated screw rotatbaly fixed to the upper end of said post and threadedly received in said housing, said screw being disposed parallel to said post and positioned between said post and motor.

3. The grinder of claim 2 in which said motor is equipped with a rotatable shaft, the axes of shaft, screw, post and member being generally coplanar.

4. The grinder of claim 1 in which said housing is equipped with a lower edge concentric to said cup, said cup being also equipped with a lower edge with the lower edge of said housing being spaced above the lower edge of said cup, said lower edge of said housing being equipped with an apertured ring for delivering cooling fluid on work supported on said support.

5. A surface grinder, comprising (A) a base providing a top surface,

(B) an elongated, vertically-extending post secured to said surface,

(C) a housing slidably, rotatably mounted on said post,

(D) a block rotatably mounted atop said post and equipped with screw means connected to said housing for maintaining said housing at a selected spaced distance above said surface,

(E) a motor in said housing and equipped with a depending shaft extending parallel to said post, said shaft adjacent its lower end being equipped with grinding cup means,

(F) means in said housing for self-lubricating said shaft, and bearings interposed between said block and screw means and between said block and post, said block being equipped with a depending stabilizer bar, said housing being equipped with vertically spaced-apart brackets slidably enclosing said bar.

6. The structure of claim 5 in which said screw means is equipped with a hand wheel positioned above said block.

7. The grinder of claim 1 in which said housing is equipped with means for delivering a coolant liquid onto work on said support in a generally circular pattern.

References Cited in the file of this patent UNITED STATES PATENTS 1,857,549 Iereczek May 10, 1932 2,603,041 Bowen July 15, 1952 2,611,220 Selby Sept. 23, 1952 

1. A SURFACE GRINDER, COMPRISING (A) A BASE, (B) AN UPSTANDING POST ON SAID BASE, (C) A WORK SUPPORT ON SAID BASE ADJACENT TO BUT SPACED FROM SAID POST, (D) A HOUSING SLIDABLY, ROTATABLY MOUNTED ON SAID POST, (E) A MOTOR MOUNTED IN SAID HOUSING AND EQUIPPED WITH A GRINDING CUP AXIALLY RELATED TO THE MOTOR, SAID CUP BEING POSITIONABLE OVER SAID SUPPORT, AND (F) MEANS ON SAID POST FOR SLIDING SAID HOUSING THEREON AND FOR STABILIZING SAID HOUSING, SAID MEANS INCLUDING AN ELONGATED ROD-LIKE MEMBER ARRANGED PARALLEL TO AND SPACED FROM SAID POST, SAID HOUSING BEING SLIDABLY MOUNTED ON SAID MEMBER WITH SAID POST BEING POSITIONED BETWEEN SAID MEMBER AND MOTOR. 